The present invention relates to an application function in an audio/video system comprising a television receiver (hereinafter referred to as a TV), a video cassette recorder (hereinafter referred to as a VCR) and so forth being interconnected as an integrated system.
Traditionally, an audio/video system comprising both a TV and a VCR has not provided any function of controlling the component equipment items or inquiring as to the states of those equipment items with respect to one another. It has resulted in hardly implementing a function of networking the component equipment items.
In order to watch a video cassette, the conventional audio/video system has required a user not only to press a "play" button on the VCR but also to turn on a power switch of the TV. And, if the TV and VCR communicate a video and an audio signal with each other through an AV-connected path, the system has also required the user to switch an input mode into "a video mode", and if they communicate these signals through an RF-connected path, to switch the TV channel to a VCR-leased channel.
Also, a TV tuner does not normally have channel numbers matching those of a VCR tuner. It has resulted in frequently bringing about inadvertent operational failures, for example, recording a program on a TV channel the user does not intend, even though he operates the VCR switch of the same VCR channel number as that which he is watching on the TV.